Photoresist stripping technique

ABSTRACT

A method for fabricating an integrated circuit device is disclosed. The method may include providing a substrate; forming a first material layer over the substrate; forming a patterned second material layer over the substrate; and removing the patterned second material layer with a fluid comprising a steric hindered organic base and organic solvent.

BACKGROUND

The semiconductor integrated circuit (IC) industry has experienced rapidgrowth. Technological advances in IC materials and design have producedgenerations of ICs where each generation has smaller and more complexcircuits than the previous generation. In the course of IC evolution,functional density (i.e., the number of interconnected devices per chiparea) has generally increased while geometry size (i.e., the smallestcomponent (or line) that can be created using a fabrication process) hasdecreased. This scaling down process generally provides benefits byincreasing production efficiency and lowering associated costs. Suchscaling down has also increased the complexity of processing andmanufacturing ICs and, for these advances to be realized, similardevelopments in IC processing and manufacturing are needed.

It has been observed that conventional photoresist stripping solutionsmay exhibit one or more disadvantages. For example, dry etching plasmaremoval methods and aqueous based stripping solutions may cause damageto the underlying substrate or patterning layer. The damaged layer maythen exhibit poor electric performance, poor yield, and high cost ofownership. Traditional organic stripping solutions may leave smallportions of photoresist material behind, which can result in deformitiesin subsequently deposited layers. Accordingly, what is needed is amethod and photoresist stripping solution for manufacturing anintegrated circuit device that addresses these issues.

SUMMARY

The present disclosure provides for many different embodiments. In anembodiment, a photoresist stripping composition for integrated circuitdevice patterning processes is provided. The photoresist strippingsolution may comprise an organic solvent and a steric hindered organicbase. The steric hindered organic base may include at least one of aprimary amine, secondary amine, tertiary amine, or quaternary aminehydroxide.

A method for fabricating an integrated circuit device is also disclosed.In an embodiment, the method may include providing a substrate; forminga first material layer over the substrate; forming a patterned secondmaterial layer over the substrate; and removing the patterned secondmaterial layer with a fluid comprising a steric hindered organic baseand organic solvent.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure is best understood from the following detaileddescription when read with the accompanying figures. It is emphasizedthat, in accordance with the standard practice in the industry, variousfeatures are not drawn to scale and are used for illustration purposesonly. In fact, the dimensions of the various features may be arbitrarilyincreased or reduced for clarity of discussion.

FIG. 1 is a flow chart of a method for fabricating an integrated circuitdevice according to aspects of the present disclosure.

FIGS. 2A-2D are various cross-sectional views of embodiments of anintegrated circuit device during various fabrication stages according tothe method of FIG. 1.

DETAILED DESCRIPTION

The present disclosure relates generally to methods for manufacturingsemiconductor devices, and more particularly, to a method andphotoresist stripping solution for patterning various semiconductordevice features.

It is understood that the following disclosure provides many differentembodiments, or examples, for implementing different features of theinvention. Specific examples of components and arrangements aredescribed below to simplify the present disclosure. These are, ofcourse, merely examples and are not intended to be limiting. Forexample, the formation of a first feature over or on a second feature(and like descriptions) may include embodiments in which the first andsecond features are formed in direct contact, and may also includeembodiments in which additional features may be formed between the firstand second features. In addition, the present disclosure may repeatreference numerals and/or letters in the various examples. Thisrepetition is for the purpose of simplicity and clarity and does not initself dictate a relationship between the various embodiments and/orconfigurations discussed.

With reference to FIG. 1 and FIGS. 2A-2D, a method 100 and asemiconductor device 200 are collectively described below. Thesemiconductor device 200 may be an integrated circuit, or portionthereof, that may comprise memory cells and/or logic circuits. Thesemiconductor device 200 may include passive components such asresistors, capacitors, inductors, and/or fuses; and active components,such as P-channel field effect transistors (PFETs), N-channel fieldeffect transistors (NFETs), metal-oxide-semiconductor field effecttransistors (MOSFETs), complementary metal-oxide-semiconductortransistors (CMOSs), high voltage transistors, and/or high frequencytransistors; other suitable components; and/or combinations thereof.FIG. 1 is a flow chart of one embodiment of the method 100 for makingthe semiconductor device 200. FIGS. 2A-2D are various cross-sectionalviews of the semiconductor device 200 according to one embodiment, inportion or entirety, during various fabrication stages of the method100. It is understood that additional steps can be provided before,during, and after the method 100, and some of the steps described belowcan be replaced or eliminated for additional embodiments of the method.It is further understood that additional features can be added in thesemiconductor device 200, and some of the features described below canbe replaced or eliminated for additional embodiments of thesemiconductor device 200. The method 100 and the correspondingsemiconductor device 200 is exemplary only and not intended to belimiting. For example, the structure of the IC device depicted in FIGS.2A-2D is exemplary only and similar methods may be used to form anysimilar device.

The method 100 is a lithography method for use in manufacturing asemiconductor device. The terms lithography, immersion lithography,photolithography, and optical lithography may be used interchangeably inthe present disclosure. Photolithography is a process used inmicrofabrication, such as semiconductor fabrication, to selectivelyremove parts of a thin film or a substrate. The process uses light totransfer a pattern (e.g., a geometric pattern) from a photomask to alight-sensitive layer (e.g., photoresist, or simply “resist”) on thesubstrate. The light causes a chemical change in exposed regions of thelight-sensitive layer, which may increase or decrease solubility of theexposed regions. If the exposed regions become more soluble, thelight-sensitive layer is referred to as a positive photoresist. If theexposed regions become less soluble, the light-sensitive layer isreferred to as a negative photoresist. Baking processes may be performedbefore or after exposing the substrate, such as a post-exposure bakingprocess. A developing process selectively removes the exposed orunexposed regions with a developing solution creating an exposurepattern over the substrate. A series of chemical treatments may thenengrave/etch the exposure pattern into the substrate (or materiallayer), while the patterned photoresist protects regions of theunderlying substrate (or material layer). Alternatively, metaldeposition, ion implantation, or other processes can be carried out.Finally, an appropriate reagent removes (or strips) the remainingphotoresist, and the substrate is ready for the whole process to berepeated for, the next stage of circuit fabrication. In a complexintegrated circuit (for example, a modern CMOS), a substrate may gothrough the photolithographic cycle a number of times.

Referring to FIGS. 1 and 2A, at block 102 of the method 100, a substrate210 is provided. The substrate 210 may be a semiconductor substrate thatincludes an elementary semiconductor including silicon and/or germaniumin crystal; a compound semiconductor including silicon carbide, galliumarsenic, gallium phosphide, indium phosphide, indium arsenide, and/orindium antimonide; an alloy semiconductor including SiGe, GaAsP, AlInAs,AlGaAs, GaInAs, GaInP, and/or GaInAsP; or combinations thereof. Thealloy semiconductor substrate may have a gradient SiGe feature in whichthe Si and Ge composition change from one ratio at one location toanother ratio at another location of the gradient SiGe feature. Thealloy SiGe may be formed over a silicon substrate. The SiGe substratemay be strained. Furthermore, the substrate may be a semiconductor oninsulator (SOI). In some examples, the substrate may include a doped epilayer. In other examples, the silicon substrate may include a multilayercompound semiconductor structure. Alternatively, the substrate 210 mayinclude a non-semiconductor material, such as a glass substrate forthin-film-transistor liquid crystal display (TFT-LCD) devices, or fusedquartz or calcium fluoride for a photomask (mask).

The substrate 210 may comprise one or more material layers. The one ormore material layers may comprise one or more high-k dielectric layers,gate layers, hard mask layers, interfacial layers, capping layers,diffusion/barrier layers, dielectric layers, conductive layers, othersuitable layers, and/or combinations thereof. A high-k dielectric layermay include hafnium oxide (HfO₂), hafnium silicon oxide (HfSiO), hafniumsilicon oxynitride (HfSiON), hafnium tantalum oxide (HfTaO), hafniumtitanium oxide (HfTiO), hafnium zirconium oxide (HfZrO), metal oxides,metal nitrides, metal silicates, transition metal-oxides, transitionmetal-nitrides, transition metal-silicates, oxynitrides of metals, metalaluminates, zirconium silicate, zirconium aluminate, zirconium oxide,titanium oxide, aluminum oxide, hafnium dioxide-alumina (HfO₂—Al₂O₃)alloy, other suitable high-k dielectric materials, and/or combinationsthereof. A gate layer may comprise silicon-containing materials;germanium-containing materials; metal, such as aluminum, copper,tungsten, titanium, tantulum, titanium nitride, tantalum nitride, nickelsilicide, cobalt silicide, TaC, TaSiN, and/or TaCN; other suitablematerials; and/or combinations thereof. In one example, the gate layercomprises a layer of silicon dioxide and a layer of high-k dielectricmaterial. The gate layer may be doped polycrystalline silicon with thesame or different doping. The gate layer may comprise a work functionlayer. For example, if a P-type work function metal (P-metal) isdesired, TiN, WN, or W may be used. On the other hand, if an N-type workfunction metal (N-metal) is desired, TiAl, TiAlN, or TaCN, may be used.In some examples, the work function layer may include doped-conductingmetal oxide materials.

In one example, the substrate 210 includes a dielectric material. Thedielectric material may exhibit a dielectric constant ranging betweenabout 1 and about 40. In another example, the substrate 210 comprises atleast one of silicon, a metal oxide, or a metal nitride. The compositionof the substrate may be represented by a formula, MX_(b), where M is ametal or Si, X is N or O, and b ranges between about 0.4 and about 2.5.Examples of substrate compositions including at least one of silicon,metal oxide, or metal nitride include SiO₂, silicon nitride, aluminumoxide, hafnium oxide, lanthanum oxide, other suitable compositions, andcombinations thereof. In yet another example, the substrate 210comprises at least one of a metal, a metal alloy, a metal nitride, ametal sulfide, a metal selenide, a metal oxide, or a metal silicide. Thecomposition of the substrate may be represented by a formula, MX_(a),where M is a metal, X is N, S, Se, O, or Si, and a ranges between about0.4 and about 2.5. Examples of substrate compositions including at leastone of metal, metal alloy, or metalnitride/sulfide/selenide/oxide/silicide include Ti, Al, Co, Ru, TiN,WN₂, TaN, other suitable compositions, and/or combinations thereof.Also, the substrate 210 may be substantially conductive orsemi-conductive. For example, the electric resistance of the substrate210 may be less than 10³ ohm-meter.

At blocks 104 and 106, a first material layer 212 and a second materiallayer 214 are formed over the substrate 210. Alternatively, the firstmaterial layer 212 may be eliminated and the second material layer 214may be formed over the substrate 210. The first material layer 212comprises a different composition than the second material layer 214.The first and second material layers 212, 214 are coated on thesubstrate 210 to any suitable thickness by any suitable process, such asspin-on coating, chemical vapor deposition (CVD), plasma enhanced CVD(PECVD), atomic layer deposition (ALD), physical vapor deposition (PVD),high density plasma CVD (HDPCVD), other suitable methods, and/orcombinations thereof. The first material layer 212 may comprise adifferent optical property than the second material layer 214. Forexample, the first material layer 212 may comprise a substantiallydifferent refractive index (i.e., n value), extinction coefficient(i.e., k value), or T value than the second material layer 214. Thefirst and second material layers 212, 214 may further comprise differentetching resistances. The first and/or second material layers 212, 214may comprise at least one etching resistant molecule, which may includea low onishi number structure, a double bond, triple bond, silicon,silicon nitride, Ti, TiN, Al, aluminum oxide, and/or SiON.

The first material layer 212 is a patterning layer. The patterning layermay comprise one or more layers similar to those described above,including photoresist layers, antireflective coating layers (e.g., a topantireflective coating layer (TARC) and/or a bottom antireflectivecoating layer (BARC)), high-k dielectric layers, gate layers, hard masklayers, interfacial layers, capping layers, diffusion/barrier layers,dielectric layers, conductive layers, other suitable layers, and/orcombinations thereof. In one example, the first material layer 212comprises a BARC layer. In another example, the first material layer 212comprises at least one of an acid labile molecule, a polymer, photoacidgenerator (PAG), quencher, chromophore, crosslinker, surfactant, and/orsolvent.

The second material layer 214 is a photoresist layer comprising anysuitable material. The photoresist layer is a positive-type ornegative-type resist material. The second material layer 214 may have amulti-layer structure. One exemplary resist material is a chemicalamplifying (CA) resist. The second material layer 214 comprises at leastone of a polymer, a photoacid generator (PAG), a quencher (base), achromophore, and/or a solvent. The polymer may comprise an organic orinorganic polymer with a molecular weight between approximately 1000 and20,000. The polymer may include an acid cleavable polymer, an acidcatalyzed crosslinkable polymer, a polymeric pinacol, and/or othersuitable polymer. The second material layer 214 may further comprise asurfactant, a photodegradable base, a photobase generator (PBG), anelectron acceptor, and/or crosslinker.

At block 108, at least one exposure process is performed on the secondmaterial layer 214. The exposure process selectively illuminates thesecond material layer 214 by a radiation beam to form one or moreexposed portions 214A and unexposed portions 214B as illustrated in FIG.2B. The radiation beam used to expose the second material layer 214 maybe ultraviolet and/or extended to include other radiation beams, such asion beam, x-ray, extreme ultraviolet, deep ultraviolet, and other properradiation energy. In one example, the second material layer 214 isexposed to a wavelength substantially less than 250 nm. The patternedexposed and unexposed portions 214A, 214B are formed by illuminating thesecond material layer with a radiation source through one or morephotomasks (or reticles) to form an image pattern. The process mayimplement krypton fluoride (KrF) excimer lasers, argon fluoride (ArF)excimer lasers, ArF immersion lithography, ultraviolet (UV) radiation,extreme ultra-violet (EUV) radiation, and/or electron-beam (e-beam)writing. The exposing process may also be implemented or replaced byother proper methods such as maskless photolithography, ion-beamwriting, and/or molecular imprint techniques. It is understood that asingle exposure patterning process, double exposure patterning process,or multiple exposure patterning process may be performed. For example,the second material layer 214 may be exposed to a first wavelength, andthen, exposed to a second wavelength.

Subsequently, the second material layer 214 may be subjected to apost-exposure bake (PEB) process. After a pattern exposure and/orpost-exposure bake (PEB) process, the PAG in the second material layer214 (i.e., photoresist) may produce an acid and thus increase ordecrease its solubility. The solubility may be increased for positivetone resist (i.e., the acid will cleve an acid cleavable polymer,resulting in the polymer becoming more hydrophilic) and decreased fornegative tone resist (i.e., the acid will catalyze an acid catalyzedcrosslinkable polymer or cause a polymeric pinnacle to undergo pincaolrearrangement, resulting in the polymer becoming more hydrophobic).

Referring to FIG. 2C, at block 110, the second material layer 214 isdeveloped by any suitable process to form a pattern in the secondmaterial layer 214. A developing solution may be utilized to removeportions of the second material layer 214. An example of a developingsolution is tetramethylammonium hydroxide (TMAH). Any concentrationlevel of TMAH developer solution may be utilized, such as approximately2.38% TMAH developer solution. The developing solution may remove theexposed or unexposed portions 214A, 214B depending on the resist type.For example, in the present example, the second material layer 214comprises a negative-type resist, so the exposed portions 214A are notdissolved by the developing solution and remain over the first materiallayer 212 (or substrate 210). If the second material layer 214 comprisesa positive-type resist, the exposed portions 214A would be dissolved bythe developing solution, leaving the unexposed portions 214B behind. Thesemiconductor device may then be subjected to a rinsing process, such asa de-ionized (DI) water rinse. The rinsing process may remove residueparticles.

The remaining exposed portions 214A (or unexposed portions 214B) definea pattern. The pattern contains one or more openings, wherein portionsof the underlying first material layer 212 (or substrate 210) areexposed. Subsequent processing may include removing the exposed portionsof the first material layer 212 and/or substrate 210 within theopenings. Alternatively, metal deposition, ion implantation, or otherprocesses can be carried out over/on the first material layer 212 and/orsubstrate 210. The second material layer 214, such as remaining exposedportions 214A, may be subjected to one or more treatment processes,including ion implantation processes, plasma treatment processes, UVtreatment processes, other suitable processes, and/or combinationsthereof. The ion implantation processes may be performed on the firstlayer 212 to implant exposed portions of the first material layer 212,also subjecting the patterned second material layer 214 to ionbombardment. The ions implanted may include arsenic, phosphorous, boron,nitrogen, carbon, germanium, oxygen, tellurium, other suitable ions. Theion bombardment may utilize halogen elements. The plasma treatmentprocesses may employ a process gas mixture comprising any suitableplasma gas, such as O₂ or nitrogen-containing compositions (e.g., N₂O,N₂H₂, etc.). The plasma treatment may utilize at least one of a halogen,halogenated or non-halogenated composition, branched or non-branchedcomposition, cyclic or non-cyclic composition, saturated or unsaturatedcomposition, alkane composition, and/or other suitable compositions. Theprocesses described may utilize any suitable temperature, such as atemperature range from about 22° C. to about 300° C. In one example, theoperation temperature ranges from about 40° C. to about 120° C. Theprocesses described may further utilize any suitable pressure, such as apressure range from about 0.9 atm to about 10 atm.

Referring to FIG. 2D, at block 112, the patterned second material layer214 (i.e., remaining portions of the second material layer 214) isremoved (or stripped) with a fluid. In cases where the patterned secondmaterial layer 214 is subjected to an ion bombardment or plasmatreatment process, the fluid strips the ion bombarded, patterned secondmaterial layer 214 and/or the plasma treated, patterned second materiallayer 214. Conventional stripping solutions may exhibit varyingdisadvantages including damage to underlying layers (e.g., firstmaterial layer 212) and/or small amounts of photoresist materialremaining on the underlying layers, which may result in deformities insubsequently formed layers. Thus, in the present disclosure, thepatterned second material layer 214 (e.g., remaining exposed orunexposed portions 214A, 214B) is removed by a fluid including a sterichindered organic base and an organic solvent. The stripping solutionincluding the steric hindered organic base may reduce substrate (orunderlying layer) damage and/or eliminate (or reduce) the amount ofphotoresist material remaining after the stripping process.

The steric hindered organic base includes a primary amine, a secondaryamine, a tertiary amine, or a quaternary amine hydroxide. The amine oramine hydroxide is represented by the formula:

R₁, R₂, R₃, and/or R₄ include an unbranched group, a branched group, acyclic group, a noncyclic group, a saturated group, an unsaturatedgroup, or an alkyl chain. R₁, R₂, R₃, and/or R₄ may have a chain carbonnumber between about 1 and about 15. In an example, the chain carbonnumber is between about 1 and about 5. In the present example, at leastone of R₁, R₂, R₃, or R₄ include a group with a size larger than abenzene group.

Z₁, Z₂, Z₃, and/or Z₄ comprise a pendant group. The pendent group may beselected from the group consisting of: —Cl, —Br, —I, —NO₂, —SO₃—, —H—,—CN, —NCO, —OCN, —CO₂—, —OH, —OR*, —OC(O)CR*, —SR, —SO₂N(R*)₂, —SO₂R*,SOR, —OC(O)R*, —C(O)OR*, —C(O)R*, —Si(OR*)₃, —Si(R*)₃, or an epoxylgroup. R* includes at least one of hydrogen, an unbranched or branchedgroup, a cyclic or noncyclic group, a saturated or unsaturated group, analkyl group, an alkenyl group, or an alkynyl group.

The organic solvent may comprise any suitable solvent, such as dimethylsulfoxide (DMSO), tetrahydrofuran (THF), propylene glycol monomethylether (PGME), propylene glycol monomethyl ether acetate (PGMEA),ethanol, propanol, butynol, methanol, ethylene, glycol, gamabutylactone,N-methyl-2-pyrrolidone (NMP), other suitable solvents, and/orcombinations thereof. In some examples, the organic solvent may compriseat least one of an alkylsulfoxide, a carboxylic ester, a carboxylicacid, an alcohol, a glycol, an aldehyde, a ketone, an acid anhydride, alactone, a halogenated or non-halogenated group, a branched ornon-branched group, a cyclic or noncyclic group, a saturated orunsaturated group, an alkane group, and/or a hetrocyclic ring.

The steric hindered organic base loading may be about 0.01% to about 40%of the organic solvent. The fluid may further comprise a strippinginhibitor, which can include at least glycol and/or diamine. Also, ithas been observed that as H₂O contamination decreases, damage tounderlying layers (or the substrate) decreases. The stripping solutionincluding the steric hindered organic base and organic solvent mayadvantageously dissolves the organic base in the organic solvent withH₂O contamination of less than 5%. After the patterned second materiallayer 214 is removed, subsequent processing may continue. For example,the semiconductor device 200 may be subjected to one or more processes,such as additional patterning, etching, deposition, etc. processes, toform additional features.

In summary, the disclosed embodiments provide a method for fabricatingan integrated circuit device. An exemplary photolithography process mayinclude processing steps of photoresist coating, soft baking, maskaligning, exposing, post-exposure baking, developing, hard baking,and/or photoresist stripping. A photoresist stripping solution of thepresent disclosure includes a steric hindered organic base. The sterichindered organic base may provide one or more advantages, such asreduced substrate/underlying layer damage, reduced H₂O contamination,and/or improved removal of photoresist materials. It is understood thatdifferent embodiments may have different advantages, and that noparticular advantage is necessarily required of any embodiment.

The foregoing outlines features of several embodiments so that thoseskilled in the art may better understand the aspects of the presentdisclosure. Those skilled in the art should appreciate that they mayreadily use the present disclosure as a basis for designing or modifyingother processes and structures for carrying out the same purposes and/orachieving the same advantages of the embodiments introduced herein.Those skilled in the art should also realize that such equivalentconstructions do not depart from the spirit and scope of the presentdisclosure, and that they may make various changes, substitutions, andalterations herein without departing from the spirit and scope of thepresent disclosure.

What is claimed is:
 1. A method comprising: providing a substrate;forming a first material layer over the substrate; forming a patternedsecond material layer over the substrate; and removing the patternedsecond material layer with a fluid comprising a steric hindered organicbase and organic solvent, wherein the fluid has a water content of lessthan 5%, wherein the steric hindered organic base is represented by theformula:

wherein R₁—Z₁, R₂—Z₂, R₃—Z₃, and R₄—Z₄ are steric hindered functionalgroups, and further wherein R₁, R₂, R₃, and R₄ are each an alkyl groupand Z₁, Z₂, Z₃, and Z₄ are each a pendant group selected from the groupconsisting of —Cl, —Br, —I, —NO₂, —SO₃—, —H—, —CN, —NCO, —OCN, —CO₂—,—OC(O)CR*, —SR*, —SO₂N(R*)₂, —SO₂R*, —OC(O)R*, —C(O)R*, —Si(R*)₃, and anepoxyl group.
 2. The method of claim 1 further comprising, beforeremoving the patterned second material layer, performing an ionimplantation process or a plasma treatment process.
 3. The method ofclaim 1 wherein R₁, R₂, R₃, and R₄ are selected from a group consistingof an unbranched group, a branched group, a cyclic group, a noncyclicgroup, a saturated group, and an unsaturated group.
 4. The method ofclaim 1 wherein at least one of R₁, R₂, R₃, or R₄ includes an alkylgroup larger than a benzene group.
 5. The method of claim 1 wherein atleast one of R₁, R₂, R₃, or R₄ has a chain carbon number ranging betweenabout 1 and about
 15. 6. The method of claim 1 wherein the pendant groupis further selected from the group consisting of —OR, —SOR, —Si(OR)₃,and —C(O)OR, R* is selected from at least one of hydrogen, an unbranchedgroup, a branched group, a cyclic group, a noncyclic group, a saturatedgroup, an unsaturated group, an alkyl group, an alkenyl group, and analkynyl group, and R is selected from at least one of an unbranchedgroup, a branched group, a cyclic group, a noncyclic group, a saturatedgroup, an unsaturated group, an alkyl group, an alkenyl group, and analkynyl group.
 7. The method of claim 1 wherein forming the patternedsecond material layer over the substrate comprises: exposing the secondmaterial layer; and developing the second material layer to removeportions of the second material layer.
 8. A method comprising: providinga substrate; forming a second material layer over the substrate;exposing the second material layer; developing the second material layerto form a patterned second material layer; and utilizing a strippingsolution comprising a fluid with a steric hindered organic base andorganic solvent to remove the patterned second material layer, whereinthe fluid has a water content of less than 5%, wherein the sterichindered organic base is represented by the formula:

wherein R₁, R₂, R₃, and R₄ are each an alkyl group and Z₁, Z₂, Z₃, andZ₄ are each a pendant group, selected from the group consisting of —Cl.—Br, —I, —NO₂, —H—, —CN, —NCO, —OCN, —CO₂—, —OR, —OC(O)CR*, —SR*,—SO₂N(R*)₂, —SO₂R*, —SOR, —OC(O)R*, —C(O)OR, —C(O)R*, —Si(OR)₃,—Si(R*)₃, and an epoxyl group, wherein R* is selected from at least oneof hydrogen, an unbranched group, a branched group, a cyclic group, anoncyclic group, a saturated group, an unsaturated group, an alkylgroup, an alkenyl group, and an alkynyl group, and R is selected from atleast one of an unbranched group, a branched group, a cyclic group, anoncyclic group, a saturated group, an unsaturated group, an alkylgroup, an alkenyl group, and an alkynyl group.
 9. The method of claim 8further comprising performing an ion bombardment process, a plasmatreatment process, a UV treatment process, or combination thereof on thepatterned second material layer.
 10. The method of claim 8 furthercomprising performing a post-exposure baking process.
 11. The method ofclaim 8 wherein R₁, R₂, R₃, and R₄ are selected from a group consistingof an unbranched group, a branched group, a cyclic group, a noncyclicgroup, a saturated group, and an unsaturated group.
 12. The method ofclaim 8 wherein at least one of R₁, R₂, R₃, or R₄ includes an alkylgroup larger than a benzene group.
 13. A method comprising: providing asubstrate; forming a first material layer over the substrate; forming apatterned second material layer over the substrate; removing thepatterned second material layer with a fluid comprising a sterichindered organic base and organic solvent, wherein the fluid has a watercontent of less than 5% and the organic base is represented by theformula

wherein R₁, R₂, R₃, and R₄ are selected to include a group larger than abenzene group and Z₁, Z₂, Z₃, and Z₄ are selected from the groupconsisting of: —Cl, —Br, —I, —NO₂, —SO₃—, —H—, —CN, —NCO, —OCN, —CO₂—,—OC(O)CR*, —SR*, —SO₂N(R*)₂, —SO₂R*, —OC(O)R*, —C(O)R*, —Si(R*)₃, and anepoxyl group.
 14. The method of claim 13, wherein Z₁, Z₂, Z₃, and Z₄ arefurther selected from the group consisting of —OR, —SOR, —C(O)OR, and—Si(OR)₃, R* is selected from at least one of hydrogen, an unbranchedgroup, a branched group, a cyclic group, a noncyclic group, a saturatedgroup, an unsaturated group, an alkyl group, an alkenyl group, and analkynyl group, and R is selected from at least one of an unbranchedgroup, a branched group, a cyclic group, a noncyclic group, a saturatedgroup, an unsaturated group, an alkyl group, an alkenyl group, and analkynyl group.